Living body information measurement devices are known which can measure living body information such as a pulse rate and a blood pressure using information that is detected by a pressure sensor(s) in a state that the pressure sensor(s) is in direct contact with a living body part where an artery such as a wrist radius artery runs. In these blood pressure measurement devices, the positional relationship between the pressure sensor(s) and an artery influences the measurement accuracy of living body information. In view of this, as disclosed in JP-2010-220948-A, JP-2010-220949-A, JP-H02-001220-A, JP-2002-330932-A and JP-H01-288228-A, configurations that enable adjustment of the positional relationship between a living body part and a sensor(s) have been proposed.
The living body information measurement device disclosed in JP-2010-220948-A is equipped with 6×7=42 sensors to be brought into contact with a living body part and a mechanism that enables manual adjustment of the inclination of the sensors with respect to an artery direction so that the sensors can produce proper outputs.
The living body information measurement device disclosed in JP-2010-220949-A is equipped with 6×7=42 sensors to be brought into contact with a living body part. So that the sensors are kept in contact with a hand following its movement, the sensors are grouped into four blocks and the living body information measurement device is also equipped with a mechanism that enables adjustment of the respective heights of the divisional blocks.
JP-H02-001220-A discloses a living body information measurement device which is equipped with a pressure sensor to be brought into contact with a living body part and a drive unit for moving the pressure sensor in a direction that crosses an artery.
JP-2002-330932-A discloses a living body information measurement device which is equipped with a pressure sensor array to be brought into contact with a living body part and a drive unit for rotating the pressure sensor array in a plane that crosses a pressing direction of the pressure sensor array.
JP-H01-288228-A discloses a living body information measurement device which has a pressing surface that is formed with an arrangement of plural pressure sensor arrays to be brought into contact with a living body part. The living body information measurement device is equipped with a drive unit for rotating the pressing surface about an axis extending in a direction that is perpendicular to an arrangement direction of the plural pressure sensor arrays.
In the devices disclosed in JP-2010-220948-A and JP-2010-220949-A, although the state of contact between the sensors and a living body part can be varied, the contact state varies following the shape of a wrist of a user or is varied manually. Thus, the sensors cannot be positioned with sufficient consideration given to the measurement accuracy of living body information.
In the devices disclosed in JP-H02-001220-A, JP-2002-330932-A and JP-H01-288228-A, the pressure sensor(s) can be positioned taking the measurement accuracy of living body information into consideration because driving can be made so as to vary the position(s) of the pressure sensor(s) to allow it (them) to produce a proper output(s). However, when living body information is measured using information that is output from the pressure sensor(s) in a state that the pressure sensor(s) is pressed against a living body part, the position of an artery may be varied by a pressing force. It is difficult for the devices disclosed in JP-H02-001220-A, JP-2002-330932-A and JP-H01-288228-A to follow such a positional variation. Furthermore, the device of JP-H02-001220-A has a large size because it requires a mechanism for moving the pressure sensor in a direction that crosses an artery direction.